Applicants have described methods and apparatus for treating a variety of renal and cardio-renal diseases, such as congestive heart failure (“CHF”), renal disease, renal failure, hypertension, heart arrhythmia and myocardial infarction, by modulating or denervating neural fibers that contribute to renal function. This reduces renal sympathetic nervous activity, which increases removal of water and sodium from the body, and returns renin secretion to more normal levels. Normalized renin secretion may normalize renal blood flow and decrease peripheral vascular resistance. See, for example, Applicants' co-pending U.S. patent application Ser. No.: (a) 10/408,665, filed Apr. 8, 2003; (b) Ser. No. 11/129,765, filed on May 13, 2005; (c) Ser. No. 11/189,563, filed on Jul. 25, 2005; (d) Ser. No. 11/363,867, filed on Feb. 27, 2006; (e) Ser. No. 11/504,117, filed on Aug. 14, 2006; as well as U.S. Pat. No. 6,978,174. All of these applications and the patent are incorporated herein by reference in their entireties.
Many blood vessels throughout the body are innervated. Furthermore, many nerves travel in proximity to blood vessels of the body. In some patients, it may be desirable to modulate such nerves or nervous tissue (e.g., brain tissue) within or in proximity to a blood vessel to treat a neurological disorder or other medical condition. Such modulation may desirably result in alteration of the nerve function or denervation of tissue that is innervated by the nerves. However, it may be invasive or impractical to access such nerves/nervous tissue, or it may be difficult to locally modulate the nerves or denervate target tissue without excessively damaging surrounding tissues. Therefore, it would be desirable to provide methods and apparatus for intravascularly-induced denervation.